<!DOCTYPE html>
<html lang="utf-8">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<head>
     <title>钟表 2019年3月4日19点30分 by:逆火狂飙 horn19782016@163.com</title>
    </head>

     <body onload="draw()">
        <canvas id="myCanvus" width="400px" height="400px" style="border:0px dashed black;">
            出现文字表示你的浏览器不支持HTML5
        </canvas>
     </body>
</html>
<script type="text/javascript">
<!--
function draw(){
	var canvas=document.getElementById('myCanvus');	
	canvas.width=400;
	canvas.height=400;	

	context=canvas.getContext('2d');	
	context.translate(200,200);
	
	clock=new Clock(200);	
	clock.init();

	animate();
};


var context;
var clock;

function animate(){	
	context.clearRect(-200,-200,400,400);// 清屏
	
	clock.paintBg(context);
	clock.paintScale(context);
	clock.paintPointers(context);

	if(true){
		window.requestAnimationFrame(animate);
	}
}

// 钟表类
function Clock(radius){
	this.radius=radius;
	this.img;
	
	this.init=function(){
		this.img=new Image();
		this.img.src="bg.jpg";
	}

	// 画背景
	this.paintBg=function(ctx){
		ctx.drawImage(this.img,0,0,400,400,-200,-200,400,400);
		ctx.fillStyle="red";
		
		var width = ctx.canvas.width;
        var height = ctx.canvas.height;
		var BL = width / 200;
		
		var r=this.radius;
		ctx.save();//保存一下最开始时钟的环境
		ctx.beginPath();
		ctx.lineWidth = 13.8 * BL;//线要 乘上 比例
		ctx.arc(0, 0, r - ctx.lineWidth / 2, 2 * Math.PI, false);//乘上比例
		ctx.strokeStyle = "#000080";
		ctx.stroke();

		ctx.fillStyle="white";
		var hourNumber = [3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 1, 2];
		ctx.font = 18 * BL + 'px Arial';//字体也有乘比例 字符串拼接
		ctx.textAlign = 'center';
		ctx.textBaseline = 'middle';

		hourNumber.forEach(function (number, i) {
			var rad = 2 * Math.PI / 12 * i;
			var x = Math.cos(rad) * (r - 30 * BL);
			var y = Math.sin(rad) * (r - 30 * BL);
			ctx.fillText(number, x, y);
		});

		for (var i = 0; i < 60; i++) {
			var rad = 2 * Math.PI / 60 * i;
			var x = Math.cos(rad) * (r - 18 * BL);
			var y = Math.sin(rad) * (r - 18 * BL);
			ctx.beginPath();
			if (i % 5 == 0) {
				ctx.fillStyle = '#800080';
				ctx.arc(x, y, 2 * BL, 0, 2 * Math.PI, false);
			} else {
				ctx.fillStyle = '#c0c0c0';
				ctx.arc(x, y, 2 * BL, 0, 2 * Math.PI, false);
			}

			ctx.fill();
		}
		
		ctx.restore();
	};

	//  画汉字
	this.paintScale=function(ctx){
		var arr=["富强","民主","文明","和谐","自由","平等","公正","法治","爱国","敬业","诚信","友善"];
		var offset=16;

		ctx.save();
		ctx.rotate(getRad(-94.5));

		for(var i=0;i<60;i++){
			var degree=i*6;
			var x=(this.radius-offset)*Math.cos(getRad(degree));
			var y=(this.radius-offset)*Math.sin(getRad(degree));

			if((i % 5)==0){
				ctx.save();	
				
				var x1=(this.radius-20)*Math.cos(getRad(degree));
				var y1=(this.radius-20)*Math.sin(getRad(degree));

				ctx.translate(x1,y1);
				ctx.rotate(getRad(degree+96));
				ctx.font="bold 16px 宋体";
				ctx.fillStyle='white';
				ctx.fillText(arr[i/5],0,0);

				ctx.restore();
			}	
		}

		ctx.restore();
	};


	// 画指针
	this.paintPointers=function(ctx){
		var date = new Date();
		var hour=date.getHours();
		var minute=date.getMinutes();
		var second=date.getSeconds();

		ctx.font="bold 12px 宋体";
		ctx.fillStyle="white";
		ctx.fillText(hour+":"+minute+":"+second,-20,-100);
		
		var angleS=second*6;
		var angleM=minute*6;
		var angleH=hour*30+angleM/360*30;

		var width = ctx.canvas.width;
        var height = ctx.canvas.height;
		var BL = width / 200;
		
		context.save();
			context.rotate(getRad(-90));
			var x,y;
			
			// 画时针
			x=(this.radius-60)*Math.cos(getRad(angleH));
			y=(this.radius-60)*Math.sin(getRad(angleH));
			ctx.strokeStyle = "white";
			ctx.lineWidth = 3 * BL;//定义指针的宽
	        ctx.lineCap = 'round';//指针顶部为弧
				
			ctx.beginPath();
	        ctx.moveTo(-x/8, -y/8);
	        ctx.lineTo(x,y);
	        ctx.stroke();
	        ctx.closePath();
			
			// 画分针
			x=(this.radius-45)*Math.cos(getRad(angleM));
			y=(this.radius-45)*Math.sin(getRad(angleM));
			ctx.strokeStyle = "white";
			ctx.lineWidth = 2 * BL;//定义指针的宽
	        ctx.lineCap = 'round';//指针顶部为弧
			
			ctx.beginPath();
	        ctx.moveTo(-x/8, -y/8);
	        ctx.lineTo(x,y);
	        ctx.stroke();
	        ctx.closePath();

		context.restore();

		// 画秒针
		ctx.save();
			ctx.lineWidth=0.5;

			ctx.strokeStyle = "black";
			ctx.beginPath();

			var r=this.radius;
			ctx.rotate(getRad(angleS));
		    ctx.moveTo(-2 * BL, 20 * BL);//画出一个秒针 x轴-2 y轴20
			ctx.lineTo(2 * BL, 20 * BL);
			ctx.lineTo(1, -r + 18 * BL);
			ctx.lineTo(-1, -r + 18 * BL);
			ctx.fill();
				
	        ctx.stroke();
	        ctx.closePath();
		ctx.restore();
	};
}

//  常规函数:角度得到弧度
function getRad(degree){
	return degree/180*Math.PI;
}

//  常规函数:得到颜色
function getColor(index){
    if(index==0){
        return "green";
    }else if(index==1){
        return "silver";
    }else if(index==2){
        return "lime";
    }else if(index==3){
        return "gray";
    }else if(index==4){
        return "white";
    }else if(index==5){
        return "yellow";
    }else if(index==6){
        return "maroon";
    }else if(index==7){
        return "navy";
    }else if(index==8){
        return "red";
    }else if(index==9){
        return "blue";
    }else if(index==10){
        return "purple";
    }else if(index==11){
        return "teal";
    }else if(index==12){
        return "fuchsia";
    }else if(index==13){
        return "aqua";
    }else if(index==14){
        return "black";
    }
}

//-->
</script>